Submersible motorpump



1 July 8, 1947.

C. J. BLOM I SUBHERSIBLE HOTORIUIP Filed March 30 1945 20 2 H z z I 1%\flw J 1/ 1 v 4 Z 5 4M I 7 0. fl n. H 9 E: I M 2 2 H j Patented July 8,1947 UNITED STAT ES PATENT OFFICE SUBMERSIBLE MOTORPUMP Carl J. Blom,San Marino, Calif., assignor to Byron Jackson 00., Vernon, Calif., acorporation of Delaware Application March 30, 1945, Serial No. 585,685

6 Claims. (01. 103 87) pumped whether the fluid be liquid, gas,- orair,'

said fluid, however, being excluded from the interior of the motor.

An object of the present invention is to Provide a submersible motorpumpwherein the motor is filled with a dielectric fluid, usually liquidwhich may have some lubrication qualities, and incorporates meanswhereby the pressure of such dielectric fluid is maintainedapproximately equal to the discharge pressure of the associated pump.

A further object of the present invention is to provide a submersiblemotorpump which incorporates a. dielectric fluid filled sealingcompartment isolating the motor unit from the pump unit,. and simple buteffective means of maintaining the pressure therein approximately equalto the discharge pressure of the pump unit and therefore approximatelyequal to the pressure in said motor unit. I

A still further object of this invention is to provide a submersiblemotor pump which, by reason of dependable control of the relativepressures in the motor unit seal chamber and discharge side of the pump,permits use of a simple yet effective type of pump shaft seal of themechanical type as distinguished from the liquid type, so that the motorpump may operate in any position. An example of the mechanical type ofseal is shown in the U. S. Patent No. 2,002,913, issued May 28, 1935, toMendenhall and Van Horn. An example of a liquid seal may be seen in U.S. Patent No. 2,002,914, issued May 2-3, 1935, to Mendenhall and VanHorn.

With the above and other objects in view, reference is directed to theaccompanying drawings, in which: I v

Fig, l is a substantially diagrammatical view of one form of submersibleelectric motorpump embodying my invention.

Fig. 2 is an enlarged fragmentary sectional View of the mechanical fluidseal means employed in my electric motor pump, the view being takensubstantially through 2-2 of Fig. 1.

My motor pump is encased in a cylindrical outer shell I, the upper endof which is threaded into a continuing outer shell 2 of an adapterstructure 3 which, in turn is secured to a pipe line or hose (not shown)Supported within the adapter structure 3 is a motor head compartment 4which is spaced from the outer shell 2 of the adapter to form fluidpassages 5, One portion with the exterior of the adapter structure 3 andis here provided with a suitable terminal ele ment 6.

The upper end of the motor head compartment 4 4 is provided 'at itsupper end with a relatively large opening in which fits a cylindricalbellows 1 having corrugated walls. The bellows extends into the motorhead compartment and is adapted to expand and contract to reduce andincrease the effective volume of the motor head compartment. The outeror socket side of the bellows I is covered by a flexible liner 8,preferably formed of rubber or synthetic rubber. A perforated guardplate 9 fits over the bellows 'l.

A motor casing lil issecured to the lower end of the motor headcompartment 4. The motor casing is preferably double-walled, that is, itcomprises an inner and outer wall defining circulation passages H.

An electric motor unit 12 is contained in the casing l0 and drives ashaft l3 the upper end of which is journaled in a bearing l4 positionedin the lower end of the motor head compartment. Incorporated in theupper end of the shaft I3 is a small fluid circulating pump l5 designedto cause flow of fluid in and around the armature and field coils of themotor, and through the passages I I. The passages II as well as one sideof the circulating pump, communicate with the motor head compartment 4.

It is intended that the motor and the motor head compartment becompletely filled with dielectric fluid which serves not only toinsulate the parts of the motor, but also to cool the same and tolubricate the bearings.

The lower end of the motor casing I0 is joined to the upper end of aseal chamber housing IS, in the upper end of which is set a bearing I!for the shaft l3.

The shaft I3 extends through the seal chamber housing l6 through upperand lower fixed seal collars I8. Within the seal chamber housing 16 theshaft I3 is provided with rotating seal collars IS. The sets of collarsI8 and I9 have flat mating faces 20. The fixed seal collars -l8 fitloosely on the shaft l3, whereas the rotating seal collars are providedwith packing glands 2|. In addition, the rotating seal collars [9 areurged axially on the shaft l3 by means of springs 22 which arepositioned between the packing glands 2| and abutment collars 23'secured to the shaft i3.

The seal chamber housing I6 is provided with a bellows 2'4 similar tothe bellows I, but prefof the motor head compartment communicates erablyof smaller capacity. The bellows 24 is and rotating collars l8 andlocated in one of the side walls of the seal chamber housing, and isprovided with a liner 25 on its outer or socket side, and covered by aperforated cover plate 26.-

The seal chamber housing 16 may be integral with a mounting annulus 21spaced therefrom by webs 28. Pump dischargepassages 29 are formedbetween the seal chamber housing 16 and the mounting annulus. Thesepassages continue upwardly between the motor casing l and outer sealcommunicating with the fluid passages 5.

The under side of the seal chamber housing It and the annulus 21 definea pump chamber 29 in which is mounted a pump impeller 30 secured on theshaft l3.

A low pressure chamber 3| is formed between the impeller 30 and theunder side of the seal chamber housing l6, so that the lower seal meansbetween the shaft and the interior of the seal chamber housing l is atall times exposed to the intake or low pressure side of the pump. Thelowpressure chamber [3 is maintained at the intake pump pressure byreason of a port 32. An intake cage 33 covers the annulus 21 andsupports a pump bearing 34 into which extends the lower end of the shaft[3.

The mounting annulus 2'! may be hollow and communicate with the sealchamber housing to provide additional fluid capacity. A filler pipe 35extends from the annulus 21 into the intake cage 33 for the purpose offilling the mounting annulus and seal chamber housing with a dielectricfluid, preferably identical with the fluid contained in the motor andmotor head compartment.

By reason of the fact that both of the bellows I and 24 are exposed tothe discharge pressure of the pump, they tend within the limits of theirmovements, to maintain equal the fluid pressure in the seal chamber andthe motor chamber. Practically, however, the pressure in the motorchamber may be slightly less than that in the seal chamber, due to thepressure drop between the bellows 24 and the bellows 'I along the pumpdischarge passage; but in any event the pressure, insofar as operationof the bellows is concerned,

' need not rise in the motor compartment above that in the seal chamberformed by the seal housing I6.

If, however, any predetermined pressure differential is desired, or ifit is desired to maintain the pressure in the seal compartment or themotor compartment, or both, above that of the discharge pressure of thepump, the bellows themselves, may exert a spring force, or be providedwith auxiliary springs to exert a predetermined pressure in excess ofthe fluid pressure applied from the pump discharge passage. Conversely,a slightly lower pressure may be maintained in either or both the motorand seal compartments, by causing the spring pressure of the bellows tobe exerted in the opposite direction.

The shaft sea] means provided by the fixed is are such that as long asthe pressure in the seal chamber exceeds that in the motor compartment,or the pressure existing in the low pressure chamber 3|, the seals aremaintained closed. If the pressure in the motor compartment shouldexceed that in the seal chamber by a predetermined amount as determinedby the springs 22, the upper seal means may-open and permit transfer ofdielectric fluid from the motor compartment to the seal compartment.This, however, cannot occur until the bellows 24 has expanded itsmaximum amount.

The capacities of the bellows 24 and 1 are such as to permit the normalexpansion and contraction of the dielectric fluid as it is heated duringoperation and cooled between operations. The capacity of the bellows 'Imay be large enough to permit a predetermined loss of dielectric fluidfrom the motor compartment into the seal compartment, to compensate forany loss from the seal compartment which may occur.

. By reason of the bellows and their relationship to the motor and sealcompartments, and the use or type of mechanical seal herein described,it is obvious that the motorpump may be mounted in any position,although preferably it is located with the pump unit at its lower end.

Many other embodiments of the invention may be resorted to withoutdeparting from the spirit of the invention.

I claim:

1. A submersible motor pump, comprising: an inner shell structuredefining isolated and fluid filled motor and sealing compartments; anelectric motor in said motor compartment; an outer shell structurearound said inner shell and defining a passageway for pumped fluid; apump unit within said outer shell and at the sealing compartment end ofsaid inner shell including an impeller adapted to deliver fluid to saidpassageway, a shaft for said impeller extending therefrom through saidsealing compartment to said motor compartment; sealing means for saidshaft to maintain the isolation of said sealing compartment; andexpansible and contractible membranes set in the walls of said sealingand motor compartments, said membranes maintaining a sealbetween saidcompartments and said passageways, but transmitting to the fluid withinsaid compartments the pressure of the fluid in said passageways.

2. A submersible motorpump, comprising: a motor unit; a pump unit; ashaft connecting said units; a shell housing said motor unit anddefining a sealing chamber between said units throu h which extends saidshaft; sealing means for said shaft to isolate said sealing chamber fromsaid motor unit and said pump unit; pump discharge conduit meansemploying said shell as a wall thereof and communicating with said pumpunit; a dielectric liquid filling said motor unit and sealing chamber;and bellows in said motor unit and said sealing chamber and exposed tothe fluid pressure in said conduit means to subject the dielectricliquid in said motor unit and sealing chamber to the pressure in saidconduit means.

3. In a motor pump wherein a motor unit is in a fluid-filled sealedmotor compartment separated from a pump unit by a fluid-filled sealingcompartment through which extends a drive shaft, the combination of:mechanical seal elements surrounding said shaft and located to separatesaid sealing compartment from said motor compartment and from said pumpunit, the seal element between said sealing compartment and motorcompartment positionedto open for admission of dielectric fluid intosaid sealing compartment when the pressure in said seal chamber falls apredetermined amount below the pressure in said motor compartment;bellows units for each compartment, one side of each bellows exposed tothe pressure in its corresponding compartment, the other side thereofexposed to the discharge pressure of said pump unit, said bellowstending within their volumetric capacity limits, to maintain thepressures in said compartments equal.

ment between said sealing compartment and motor compartment opens toadmit fluid from said motor compartment.

5. In a motor pump wherein a motor unit is in a fluid-filled sealedmotor compartment separated from a pump unit by a fluid-filled sealingcompartment through which extends a drive shaft, the combination of: afirst mechanical seal element for said shaft between said sealingcompartment and said motor compartment arranged to open to admit fluidto said sealing compartment from said motor compartment when thepressure in said motor compartment exceeds the pressure in said sealingcompart ment by a predetermined value; a second mechanical seal elementfor said shaft between said sealing compartment and said pump unitexposed to the intake pressure of said pump unit; bellows units for eachcompartment, one side of each 6 bellows exposed to the pressure in itscorrespondin; compartment. the other side thereof exposed to thedischarge pressure of said pump unit, said bellows tending thereby tomaintain the pressures in said compartments equal.

6. A construction as set forth in claim 5, wherein the sealingcompartment bellows unit has a lesser capacity than the motorcompartment bellows, whereby upon lowering of the volume of fluid insaid sealing compartment below the compensating capacity of its bellows.said first mechanical seal element opens to admit fluid from said motorcompartment.

CARL J. BLOM.

REFERENCES clrnn The following references are of record in the file ofthis patent:

